Working out date of manufacture

Hi,

I know similar questions get asked pretty regularly, but I'm hoping someone can help me pin-down the ages of my two bikes (a TTR250 and an XT225).

The log books give a "declared date of manufacture", as they are greys, but I'm not sure these are totally reliable (I know they should be but...). I've got a couple of answers from t'internet, but I'd welcome a second opinion!

The frame numbers are 4GY-0002xx and 4JG-1652xx (I do have the whole numbers, but a bit scared of publishing them, sorry!).

Thanks chaps !

Bernie